The Pasteur Institutes of the International Network (RIIP) are strongly involved in research on the AIDS virus and on the disease itself. The wide distribution of network institutes, particularly in Africa and South-East Asia, is important when considering that that over 90% of AIDS cases are found in the South…

Between 6 and 10% of circulating HIV-1 strains are resistant to certain antiretroviral drugs. Increasing use of these drugs in countries with high HIV prevalence requires the parallel development of surveillance programs to monitor drug resistance.

Institutes from the International Network take part in this "drug resistance" program , thanks to the support of the French National Agency for AIDS Research (ANRS) and the Ministry of Foreign Affairs (MAE).

The first step in the program consisted in implementing technologies for the identification of drug resistance, using standardized methods and quality controls common to the different laboratories involved. The techniques chosen are those used by the French network for antiretroviral drug resistance developed by ANRS and by ResNet (Resistance Network) of WHO, a network to which the RIIP Institutes are affiliated.

The program also aims at standardizing algorithms used to interpret resistance mutation patterns and focuses in a first stage on the mother-to-child transmission issue. The studies focus in particular on the research of resistance mutations to nevirapine, a drug that can prevent maternal transmission of HIV (studies led in particular in Bangui, Yaounde, and in Ho Chi Minh City, Pnom-Penh). It is now recognized that pregnant women treated with nevirapine can develop a resistance to the drug very rapidly, which raises issues for treatment during subsequent pregnancies. The "drug resistance " program of the RIIP is managed in close collaboration with ANRS.

Pasteur Institutes involved in this program are located in the following countries :
- Countries from the Priority Solidarity Zone (FSP funding) : Algeria, Morocco, Central African Republic, Cameroon, Madagascar, Vietnam, Cambodia

The Pasteur Centre located in Yaounde, Cameroon, initiated a program for the prevention of mother-to-child transmission of HIV/AIDS, in collaboration with teams at the Paris Pasteur Institute and with the support of the Glaxo Foundation. These studies led to the implementation of a national program for the therapeutic prevention of HIV-1 mother-to-child transmission and for the monitoring of pregnant women in Cameroon.

AIDS - tuberculosis co-infections in Cambodia

The Pasteur Institute from Cambodia contributes to a clinical ANRS trial started in 2005. This trial is coordinated by the "Cambodian Health Committee" for the South and by the Kremlin-Bicêtre Hospital, Paris, for the North. The Pasteur Institute in Paris and an American team (Harvard Medical School) are also involved. This trial aims at identifying the best time to administer antiretroviral drugs to HIV+ patients with TB. This issue is complex because of drug interactions between key molecules of TB treatment and certain antiretrovirals, which may prevent the concomitant use of the two treatments. In addition, the immune reconstitution achieved with antiretroviral treatment can be associated to a serious worsening of TB. Results from this program will benefit the whole international medical community.

Another problem specific to the South is that of yellow-fever vaccination in immuno-compromised patients: the effect of the vaccine, based on the attenuated yellow-fever virus strain 17D, has not yet been characterized in HIV+ individuals. Sanitary constraints necessitate the mass vaccination of population of unknown HIV status (it is estimated that over 10% of the population is HIV+ in countries where yellow-fever is endemic). A study is therefore planned in Senegal. it will be led by the Dakar Pasteur Institute, in collaboration with the Paris Pasteur Institute, and will aim at evaluating the potential risk of yellow-fever vaccination in HIV+ individuals.

These few examples are non-exhaustive, since many other HIV/AIDS topics are being studied in the RIIP, including the genetic diversity of HIV-1 in North-Western Russia, studied at the St-Petersburg Pasteur Institute, or the issue of HIV/malaria co-infections, studied at the Bangui Pasteur Institute in the Central African Republic. These examples illustrate the scope of HIV/AIDS research led in the hardest hit countries.

(December 2005)

To obtain information on AIDS research at the
Pasteur Institute of Paris (France), see the following activity reports.

For more information on the International Network of Pasteur Institutes, follow this link.